Portable hand-held terminals are employed in many different industries, and are typically assembled by enclosing internal electrical components within a housing. Generally, a desirable characteristic of such terminals is that they can readily function, while a respective user performs other more demanding tasks. For example, a user may find it necessary to operate a data terminal with one hand, while leaving the other hand free. In particular, the user may find it desirable to lift or otherwise shift small items of inventory with one hand, while simultaneously scanning them with the portable scanner held in the other hand.
Typically, a data terminal equipped with an optical character set reader is coupled with a handle assembly for ease of gripping by a user. The handle grip assembly further includes a trigger mechanism that is connected to the data terminal so that the user, by depressing the trigger, command the data terminal's optical character set reader to scan a target, e.g., bar code symbols. Upon depressing the trigger, a laser beam generated by a laser source, for example, a gas laser tube or a semiconductor laser diode, is optically focused by an optical train into a generally circular laser beam spot on a target symbol. The beam spot is swept by a scanning component over the symbol and forms a scan pattern thereon. Laser light reflected off the symbol is detected by a light sensor, e.g. a photodiode, which is mounted together with the laser source and the optical train in the terminal unit.
The symbol itself is a coded pattern comprised of a series of bars of various widths. The bars are being spaced apart from one another to bound spaces of various widths and the bars and spaces have different light-reflective properties. Although dimensions may vary, depending on the particular application and the density of the symbol, each bar and space of a bar code symbol typically used in the retail industry to identify retail products measures on the order of thousandths of an inch (mils). In practice, the generally circular laser beam spot has a cross-sectional diameter on the order of 6 to 10 mils. Such bar code symbols are widely used for a multitude of applications, for example sales order entry, inventory control, marketing data collection, asset management, and the like. In particular, the use of bar codes has become so common they are now typically found on store shelves and on packages, containers, cans, and the like in which merchandise is packaged and sold. As a consequence, a variety of bar code scanners for reading and decoding bar codes are manufactured and marketed.
Generally, bar code scanners fall within one of two types, namely; laser scanners and contact scanners. A laser scanner can resemble a “gun” in that it generally has a brick or bar shaped element and a handle with a trigger. This design aids a user in aiming the laser scanner properly at the target, as well as controlling and balancing the laser scanner which, due to its weight, can cause fatigue in the hands and wrists of a user.
By aiming the brick shaped element of the scanner in a direction of a code symbol and pressing the trigger, a laser scanner scans or “reads” a bar code. As such, the laser source emits a light beam that exits the brick shaped element of the laser scanner and strikes the bar code. Subsequently, a portion of the light beam is reflected back through the brick element in such a manner as to strike a detector, which then transmits the information electronically for further processing, e.g., to a microprocessor.
The second type of scanners, contact scanners are sometimes also referred to as “pencil wands” due to their narrow, pencil-like shape. Contact scanners scan or “read” a bar code by emitting visible red or infrared light such as, for example, from an LED which strikes the bar code while the scanner is moved across the bar code in a linear direction with the tip of the scanner touching the bar code label. Similar to a laser scanner, a portion of the light is reflected back into the wand in such a manner as to strike a detector which then transmits the information electronically for further processing.
Traditionally, laser scanners and contact scanners were generally simple devices that included only the requisite optics. Such scanners could be connected via a cable to a separate computer and an operator viewed the requisite data on a display of the computer and employed the computer key board to input any data. As such, the scanners did not include a keyboard, a display, or a memory.
However, more recent versions of such bar code readers have included some form of a keypad, a display, a CPU and a memory, for example a wireless laser scanner that incorporates an internal battery and memory to save the data as the operator scans bar codes has been introduced. Moreover, many such bar scanners employ various accessories for different types of applications. The constant adding and replacing of the required accessories cause wear and tear in the body of the hand held scanner that is generally formed from plastic or rubber. Such abrasion of the plastic body shortens a life cycle of the portable scanner. At the same time, wrapping the accessories around the body of the scanner reduces a user's grip balance and ease of use, causing early fatigue for a user. Moreover, often the hand held scanner needs to be oriented at various angles for a proper reading of the bar code symbol display. At such slanted angles, it is typically difficult for a user to readily observe the display area window of the scanner, should a reading becomes necessary during the use of the hand held scanner.
In addition, many such scanners are generally designed for employing a specific key pad configuration and are not adapted to employ key pads with wider configurations than the width of the scanner. Thus, their flexibility of use is limited.
Therefore, there is a need to overcome the aforementioned deficiencies associated with conventional scanning devices.